SafetyGuidelines forChemical Demonstrations
AmericanChemicalSocietyDivisionof ChemicalEducation
Appropriate physicalandchemical demonstrations inthe classroomor inapublicvenuehaveboth educationaland motivationalvalue andarea long-standingpedagogyinchemical education. Individuals planning chemical demonstrations havearesponsibilitytofollowanddocumentsafelaboratory practicesforeachdemonstration. Theseguidelines havebeen createdbasedoncurrentbestpracticesand provideachecklistofkeyissues for demonstratorsto assurethatchemical demonstrationsareconductedsafely andwithoutincident.Becausenosuchset of guidelinescanaddressall possibleissues, only personswhohaveappropriate educationandexperiencein chemistryandchemical safety should perform chemical demonstrations. Accordingly, these guidelines are intended for use only by experienced chemical practitioners.
BeforetheDemonstration
1. Always followatested,writtenprocedure thatincludescomprehensivesafetyprecautions.Planthe demonstrationatthesmallestscale possible forthe locationandviewers.
2. Review thesafetyprecautionswhichwill help youidentify thepotential hazardsinvolved inthe demonstrationandunderstandtherisksduetoexposureand/or improperhandlingof achemical, process,or procedure.Effectivesafetyprecautions provideeasy-to-followinstructionsto minimizerisk andpreventunplanned incidentsthatcouldresult in injury orpropertydamage.
3. If a writtenprocedureisnotavailable,or safetyprecautions arenotclear, performan independent hazardandriskassessmenttoidentify thepossiblehazards andevaluatetherisks. Intherisk assessment, considerthepedagogicalvaluecomparedtothe risk.Writethedemonstrationprocedure with appropriatesafetyprecautionstoprotectagainstthe hazards andreducerisk. Refertothese guidelinesas youwritethe demonstrationprocedure,andretaintheprocedure onfile forfutureuse.
4. Alwayspracticea demonstrationbeforepresentingit beforestudentsor anaudiencefor thefirsttime.
5. Ensurethatalldemonstrationsareappropriate fortheroombeingused andtheavailablesafety equipment.Keepall exitpaths clear.Checktheventilationinthedemonstrationareatoensurethat participantsandaudiencememberswill notbeexposed to harmfulquantitiesoftoxicgasesorchemical vapors.Theuseof afumehood is required for anydemonstrationthatusesor producesasubstance with aTLV lessthan50ppm (checktheSDS for theTLVs of allchemicals).
6. ConsultcurrentSafetyData Sheets(SDS) andreviewthesafehandlinginformationforall chemicals used inthedemonstration.
7. Prepareandfollowasafetychecklistfor all combustiondemonstrationsinvolvingtheuseofa flammable liquid.Dispense onlythe amountoftheliquidrequired BEFOREbeginningthe demonstration. Capthe solvent bottleandREMOVE itfromthedemonstrationareabeforeapplyingthe ignitionsource.NEVER addmoreflammableliquidtoa combustiondemonstrationonceitisunderway.
8. Ensurethatobserverswillbeasafedistance(10feetormore)or areprotectedbyaphysical barrier, suchasa polycarbonateshield,fromthe demonstrationareawhen workingwithflammable, corrosive or toxicsubstances. Inasmall settingsuch as aclassroomorlab, all participantsandobserversmust wearappropriateeyeprotectionatall times.
9. Ensurethereis anappropriatefireextinguisher onhandwhenevertheslightest possibilityoffireexists andthatyouhavethe knowledge,experienceandtrainingtouseitproperlyin theeventof an emergency.
10.Keep aspillkitnearbytocontain, absorb, andneutralizeanyspilledchemicals.
11.Plan forappropriate handlingordisposalofreactionbyproductsorexcesschemicals in accordancewith institutional policies.
DuringtheDemonstration
12.Wear appropriate personalprotectiveequipment(PPE)forthelevelof riskasdetermined bythe assessment,suchaschemical splashgoggles, chemical-resistant gloves,andalabcoat,toprotect againstthe hazards.Activeparticipants mustalsowear appropriate PPE.
13.Providesafetyshieldprotectionwheneverthereistheslightestpossibilitythat acontainer,its fragmentsorthecontentscouldbepropelledwith sufficient force tocauseexposureand/or personal injury.
14.Warn membersoftheaudiencetocovertheirears ifaloudnoiseisanticipated.
15.Participantsandspectatorsmustnottaste anyfoodornon-foodsubstancesusedinthedemonstration.
16.Donotperformdemonstrations inwhichpartsofthe humanbodywillbeplacedin danger(suchas placingdryicein themouthor dippinghands intoahazardousliquid).
SpecialNotesforOutreachorPublicDemonstrations
17.Ensureproperpackagingandsecondarycontainmentfor thesafetransportof allchemicals toandfrom off-sitelocations. MaterialsofTrade(MOT)exceptionstoDepartmentofTransportationrequirements allowforthe transportofcertain hazardousmaterialswithoutalicenseor shippingpapersprovided certainguidelinesaremet.Therearestrict limitsontheamountsofmaterial,dependingonthehazard. Visitthe linksbelowformoreinformationabouthazardclasses,packagingrequirements,and restrictionsontheamounts ofchemicals.
18.Notifysecurityand/or administratorsthatyouwill be performingdemonstrations. If publicspacewillbe used for demonstrationsinvolvingfire,contactthelocalfiredepartmenttodetermineifthe demonstrationsmeetlocalfireandbuildingusecodes.
19.Provideawrittendemonstrationprocedure, includingcomprehensivesafetyprecautions andrisk assessments, whenevertheaudiencewill beencouraged toconductthedemonstrationatanothertime.
References
NFPA45:StandardOn FireProtectionForLaboratoriesUsingChemicals
U.S.ChemicalSafetyBoard:KeyLessons forPreventingIncidentsfromFlammableChemicals inEducational Demonstrations
PrudentPracticesintheLaboratory
Disclaimer:Theguidanceinthisdocumenthasbeencompiledbyrecognizedauthoritiesfromsourcesbelievedtobe reliableandtorepresentthebest practicesonthe subject. Theseguidelinesareintendedtoserveonlyasa startingpoint forgoodpracticesanddonotpurporttospecifyminimallegalstandardsortorepresentthepolicyoftheAmerican ChemicalSociety. Nowarranty,guarantee,orrepresentationismadebytheAmericanChemicalSociety or the ACSDivision of Chemical Education astotheaccuracy orsufficiencyoftheinformationcontainedherein,and neither theSociety nor the Divisionassumeanyresponsibilityinconnectiontherewith.
Copyright 2017, ACS Division of Chemical Education, Inc.Permission is hereby granted to reprint or copy these guidelines provided that they are reproduced in their entirety with no changes.
Printed in the Journal of Chemical Education, Volume xx, Number x, Month, p. XXX.